Well, you are correct, there are much more suitable light sources out there for various tasks and conditions. My recommendation is based on having carried both the flat pushbutton lithium powered single LED lights and the AAA and AA powered aluminum tube light with one or more LEDs. I can swing either way, but for now I have two of the photon type lights in my pocket, and they've been there for a couple years now working just fine for what I need. I haven't had to replace batteries despite almost daily use, and they are no more encumbering than my keyring is without them, not that the little AAA light I carried before that was any moreso. From a size perspective, the photon type are both smaller and lighter than the tube type flashlights. They may not be as durable, but they work, and will do what I need them to do in both day to day use and postulated likely survival situations. If I really thought I would need more light than this, I would of course pack along one of my 3 watt Luxeon flashlights, or my G2 Nitrolon, or my 1 watt Luxeon headlight.

If your pack has the room for a tube light, go for it. Really they aren't that much more encumbering than the photon style anyways. I think Doug's point was that the light he recommends is reasonably dependable, easily packable, and fairly useful, all of which contribute to it's overall effectiveness as a survival tool. Certainly there are a number of other items in his kit that can be upgraded to more durable, more powerful components, size not being so much the issue. Doug's choices have proven effective, and more is only better if it can be easily accomodated.

I would much prefer to pack my bob around with me than my edc, but for the encumberance it would generate.